The present invention relates to a channel tube coupling structure for an anti-pollution type endoscope having an insertion portion to which an outer sheath is detachably attached.
In order to prevent the insertion portion of the endoscope to be inserted within a human body from being polluted by polluted liquid within the human body, it is necessary not only to cover the insertion portion of the endoscope by an outer sheath but also to provide, in the outer sheath, a channel tube communicating with the interior of the human body so that fluid, a treatment instrument etc. can pass through the channel tube.
Such a channel tube is inserted into and disposed within the outer sheath which is arranged to cover the insertion portion of the endoscope so as to be detachable freely. Further, the channel tube is configured in a manner that the base end portion thereof extending from the base end of the outer sheath is freely coupled with and separated from tubes on the endoscope.
The endoscope is required to have various kinds of tubes such as an air supply tube, a water supply tube, a suction tube (also serves as a tube for passing a treatment member therethrough) etc. Thus, it is convenient as the aforesaid channel tube to employ a so-called multi-lumen tube in which a plurality of tubes are formed in parallel in the axial direction (see Japanese Patent Laid-Open No. 29634/1991 etc.).
However, when such a multi-lumen tube is employed as the channel tube, the coupling direction and the operation number of time for coupling with and separating from the tubes on the endoscope (for example, the air supply tube, the water supply tube, the suction tube) become plural, so that the procedures for the coupling and separation of the tubes becomes troublesome.
Accordingly, an object of the invention is to provide a channel tube coupling structure for an anti-pollution type endoscope which can easily and smoothly couple a multi-lumen type channel tube extending from the base end of an outer sheath with tubes on the endoscope and separate the multi-lumen type channel tube therefrom.